Problem: Rewrite ${((9^{9})(5^{-10}))^{-10}}$ in the form ${9^n \times 5^m}$.
Explanation: ${ ((9^{9})(5^{-10}))^{-10} = (9^{(9)(-10)})(5^{(-10)(-10)})} $ ${\hphantom{ ((9^{9})(5^{-10}))^{-10}} = 9^{-90} \times 5^{100}} $